restart syncobj timeline changes v2

[Christian König]

Tested this patch set more extensively in the last two weeks and fixed tons of additional bugs.

Still only testing with hand made DRM patches, but those are now rather reliable at least on amdgpu. Setting up igt is the next thing on the TODO list.

UAPI seems to be pretty solid already except for two changes:
1. Dropping an extra flag in the wait interface which was default behavior anyway.
2. Dropped the extra indirection in the query interface.

Additional to that I'm thinking if we shouldn't replace the flags parameter to find_fence() with a timeout value instead to limit how long we want to wait for a fence to appear.

Please test and comment,
Christian.